JP5057915B2 - Mesh-like body for anti-scouring mat and anti-scouring mat - Google Patents

Description

  The present invention relates to a scour prevention mat that is installed on the bottom of a foundation of a structure such as a breakwater constructed in water, and particularly prevents the bottom of the scour from being scoured when the bottom is sand. For scouring prevention mats.

  When a structure such as a breakwater constructed in water is installed in a place where the bottom of the water is sandy, when the sand is scoured by waves, the support structure of the foundation of the structure is fragile There is a risk of becoming.

  As a countermeasure, a sheet-like body or mat-like body is laid on the bottom of the foundation of the structure and the surface of the bottom is covered to prevent the occurrence of scouring at that part. Yes. As the sheet-like body or mat-like body, a resin sheet having a thickness of about several mm is frequently used (Patent Document 1).

In addition, for the purpose of protecting the surface of such a resin sheet when it is installed on the bottom of the water, laying such that a metal mesh is superimposed on the surface of the sheet is performed.
Japanese Utility Model Publication No. 2-018527

  However, using a wire mesh makes the shape unstable and difficult to shape, making it difficult to install on the bottom of the water. In addition, if a drought occurs during use at the bottom of the water, it will remain in the drowned state, making it difficult to return to the original flat form. Furthermore, since the wire mesh is formed of a metal material such as steel, there is a problem that it is easily rusted especially in the sea.

  Therefore, the present invention aims to solve such problems and to obtain a scouring prevention mat that is easy to install on the bottom of the water, is less likely to be deformed at the bottom of the water, and does not generate rust. To do.

In order to achieve this object, the mesh body for the scouring prevention mat of the present invention has a core-sheath type cross-sectional structure in which a heat-fusible resin is arranged in the sheath portion, and the heat-sealing of the sheath portion. The resin is woven and knitted with a thread formed of one or more fibers whose melting point is 10 ° C. lower than that of the core resin, and the heat-fusible resin is heat-sealed by heat treatment. It is characterized by being.

In the above mesh-like body, the fiber is formed of a high-viscosity polyester having a core part having an intrinsic viscosity of 0.6 to 1.0, and a sheath part is formed of a low-melting point polyester having a melting point of 100 to 200 ° C. It is preferable that

The mesh-like body is preferably composed of warp and weft and is knitted by a weft insertion Raschel knitting machine .

The scouring prevention mat of the present invention is a laminate of a resin sheet and a mesh-like body for the scouring prevention mat. Furthermore, it is preferable that the mesh-like body is bound to a sheet.

In addition, it is preferable that the weight is wrapped by the mesh-like body at the tip of the mat.

  According to the scouring prevention mat of the present invention, since the resin sheet and the resin mesh body are laminated, the sheet is disposed on the lower side and the mesh body is disposed on the upper side. When installed on the sheet, the sheet can be protected by the mesh-like body. In addition, since the mesh-like body is made of resin, it is stable in shape and easy to mold. Therefore, it can be easily installed on the bottom of the water, and it can easily be swollen when used on the bottom of the water. It will return to its original flat form. Furthermore, since it is made of resin, there is an advantage that there is no generation of rust or corrosion due to seawater.

According to the present invention, since the mesh-like body is bound to the sheet, the mesh-like body and the sheet can be easily integrated with a simple configuration.
According to the present invention, the weight is wrapped by the mesh-like body at the tip of the mat, so that the mat can be prevented from being lifted or swollen when installed on the bottom of the water. Not only can the weight be attached to the tip, it is only necessary to wrap the weight with a mesh-like body, so that the attachment can be integrated easily.

  The mesh-like body of the present invention is woven or knitted with a thread formed of a single fiber or a plurality of fibers in which the heat-fusible resin is exposed on at least a part of the surface, and the heat-fusible resins are bonded by heat treatment. Since it is heat-sealed, it can be made lightweight and have the required strength, and can be suitably used by being superimposed on a resin sheet in the scour prevention mat.

  According to the present invention, the fiber has a core-sheath type cross-sectional structure in which a heat-fusible resin is arranged in the sheath, and the heat-fusible resin in the sheath has a melting point of 10 ° C. than the resin in the core. By being low as described above, the core portion can maintain the fiber form, and the heat-sealed portion can be formed by the sheath portion to form a mesh-like body.

  According to the present invention, in the mesh-like body, the fiber is formed of a high-viscosity polyester having a core part having an intrinsic viscosity of 0.6 to 1.0 and a sheath part having a low melting point polyester having a melting point of 100 to 200 ° C. Therefore, not only can the required strength and rigidity be imparted to the mesh-like body by the core part, but also the mesh-like body can be retained after securing the adhesive strength of the heat-sealed part by the sheath part. Can do.

  According to the present invention, since the mesh-like body is composed of warp and weft and is knitted by a weft insertion Raschel knitting machine, it can have an excellent mesh form.

  In FIG. 1, 1 is a seabed and is in the form of sand. A structure 2 such as a breakwater is constructed at the illustrated location. Reference numeral 3 denotes a masonry unit, and the structure 2 is installed on the masonry unit 3 provided on the seabed 1.

  A scouring prevention mat 11 according to the present invention is laid on the sandy seabed 1. The masonry unit 3 is installed on the scour prevention mat 11 laid on the seabed 1. Specifically, the scour prevention mat 11 is disposed at the base end portion 12 in a state of being sandwiched between the seabed 1 and the masonry portion 3. The tip portion 13 of the scour prevention mat 11 is laid on the offshore side of the masonry portion 3.

  The scour prevention mat 11 has a configuration in which a resin sheet 14 and a resin mesh body 15 are laminated and integrated. However, the part in which the masonry part 3 is installed is not provided with the mesh-like body 15, but has a configuration in which only the sheet 14 is provided. That is, the mesh-like body 15 is provided only on the offshore side of the scour preventing mat 11 with respect to the masonry portion 3 corresponding to the structure 2. The front end portion 16 of the mesh-like body 15 is formed longer than the front end edge of the sheet 14 so as to project to the offshore side, and the weight 17 is wrapped and held by the front end portion 16.

  In such a configuration, if the structure 2 is constructed on the sandy seabed 1 on which the masonry portion 3 is merely installed, the structure 2 causes the waves to approach the structure 2. In addition, the sand of the seabed 1 on the offshore side is scoured, which may hinder support of the structure 2.

  On the other hand, when the scouring prevention mat 11 is laid as shown in the drawing, the scouring prevention mat 11 is held at a predetermined position by the base end portion 12 being sandwiched between the seabed 1 and the masonry portion 3. And the front-end | tip part 13 will cover the seabed 1 in the place of the offshore side rather than the structure 2. FIG. In addition, since the weight 17 is held at the tip of the scouring prevention mat 11, the tip portion 13 of the mat 11 can be prevented from rolling up even when a large wave comes. For this reason, it can prevent that the sand of the seabed 1 is scoured by waves.

  FIG. 2 shows a plan view and a front view of the scour prevention mat 11. As shown in the drawing, the sheet 14 is formed wider than the mesh-like body 15, and a protruding portion 18 from the mesh-like body 15 is formed at the end in the width direction on one side. Since the scour prevention mat 11 is formed with a predetermined width, there are cases where a plurality of mats 11 should be laid along the length direction of the structure 2 shown in FIG. In that case, the end portion 19 in the width direction on the other side of the adjacent mat 11 is laid so as to overlap the protruding portion 18.

  As the weight 17, for example, a structure in which end faces of a plurality of concrete blocks 20 having an octagonal cross section are connected with metal fittings as illustrated can be used. The total length of the plurality of concrete blocks 20 is made smaller than the width dimension of the mesh-like body 15. Then, on land, the weight 17 is placed on the distal end portion 16 of the mesh-like body 15, and the end portion 21 of the distal end portion 16 is wrapped toward the proximal end portion 12 of the mat 11, so that the weight 17 is wrapped. By binding the end portion 21 to the mesh body 15 using a resin rope or the like, the weight 17 can be wrapped by the tip portion 16 of the mesh body 15 as illustrated. Further, both ends of the wrapping portion of the weight 17 can be closed by squeezing and binding both ends of the tip portion 16 along the width direction of the mesh-like body 15. As a result, the weight 17 is completely wrapped and held by the tip portion 16.

  The sheet 14 can be constituted by, for example, a vinyl chloride sheet having a thickness of several millimeters.

  The mesh-like body 15 can be configured as shown in FIG. In FIG. 3, reference numeral 25 denotes a raschel knitted fabric knitted with warp yarns, and 26 denotes a weft yarn. For example, using a 9-gauge weft insertion Raschel knitting machine, wefts are knitted in a grid pattern on the top, bottom, left, and right, assuming that many of the same yarns as warps are twisted and arranged in four. The mesh opening of the mesh-like body 15 is suitably about several centimeters to several tens of centimeters. Since the mesh-like body 15 is knitted by a weft insertion Raschel knitting machine, it can have excellent shape stability while having an opening of several cm to several tens of cm as described above.

The yarn that constitutes the warp and the weft needs to have a core-sheath cross-sectional structure as shown in FIG. 4 , and is preferably a multifilament yarn composed of a plurality of fibers. is there. In FIG. 4, 27 is a core part and 28 is a sheath part. The core portion 27 is preferably formed of a high-viscosity polyester, and the sheath portion 28 is preferably formed of a low-melting copolymer polyester as a heat-fusible resin. In order to prevent the core portion 27 from being affected by heat during heat treatment for melting and softening the heat-fusible resin of the sheath portion 28, as the heat-fusible resin of the sheath portion 28, It is necessary to use a resin having a melting point lower by 10 ° C. or more than the resin.

  Or the monofilament yarn which consists of such a core sheath type fiber, and the spun yarn which spun multiple fibers may be sufficient. Furthermore, such a core-sheath type fiber or a fiber composed only of a heat-fusible resin and a high-melting fiber that does not melt or soften at the temperature at which the heat-fusible resin melts are mixed or spun together. It may be a thread.

  Specifically, the core-sheath type fiber is formed of a high-viscosity polyester having an intrinsic viscosity of about 0.6 to 1.0 as the core portion 27, whereby the yarn constituting the mesh-like body 15 has a high strength. Can be. As the high-viscosity polyester, polyethylene terephthalate (melting point: about 260 ° C.), polybutylene terephthalate (melting point: about 220 ° C.), polyethylene naphthalate (melting point: about 270 ° C.) and the like are suitable from the viewpoint of dimensional stability, and polyethylene terephthalate is cost effective. From this point, it is more preferable. The high-viscosity polyester of the core part 27 may be added with a weathering agent, a pigment, a colorant, a flame retardant, a matting agent and the like to such an extent that the stretchability and strength of the fiber are not impaired.

  The sheath portion 28 is preferably made of a copolyester having a melting point of 100 to 200 ° C., which has a lower melting point than that of the core portion 27, for the purpose of heat sealing described later. Further, it is preferable that the mesh-like body 15 is compatible with the core portion 27 so that the mesh-like body 15 is not easily separated from the core portion 27 when subjected to friction or bending due to waves or the like. Specifically, for example, a copolyester composed of a terephthalic acid component, an aliphatic lactone component, an ethylene glycol component, and a 1,4 butadiene component can be mentioned. Since such a copolyester has a crystalline melting point, heat treatment for heat fusion can be stably performed. Further, the obtained mesh-like body has heat resistance, and thus has an advantage that deformation due to frictional heat during transportation and work hardly occurs. The copolyester of the sheath 28 may be added with a matting agent, a coloring agent, an antibacterial agent, a flame retardant, a crystal nucleating agent, an antistatic agent, etc. to such an extent that the yarn forming property and thermal adhesiveness are not impaired. Absent.

  The mixing ratio of the core portion 27 and the sheath portion 28 is a mass ratio, and the core portion: sheath portion is preferably 1: 1 to 5: 1, and more preferably 2: 1 to 3: 1. If the sheath portion 28 is less than this range, the thermal adhesive force becomes inferior. If the sheath portion 28 exceeds this range, the ratio of the core portion 27 decreases accordingly, and it becomes difficult to obtain high strength.

  Using a yarn made of fibers having such a core-sheath-type cross-sectional structure, as shown in FIG. 3, knitting is performed, and then heat treatment is performed at a temperature not lower than the melting point of the sheath portion 28 and not higher than the melting point of the core portion 27. As a result, the fibers are thermally bonded by melting of the sheath portion 28, and the mesh-like body 15 having appropriate flexibility and rigidity is obtained. By this thermal bonding, the intersection strength between the warp knitted fabric 25 and the weft yarn 26 can be strengthened. In addition, the shape of the mesh is excellent. As the mesh-like body 15 satisfying such conditions, specifically, a product commercially available from Unitika Fiber as “Melset Grit UGMD-72000” can be suitably used. When using a mesh-like body knitted by such a weft insertion Raschel knitting machine, the wear resistance and corrosion resistance can be improved compared to the case where a resin sheet is covered with a wire mesh using zinc aluminum alloy plating wire. In addition, it can prevent the occurrence of rust, and also has flexibility, so that it can respond to deformation of the water bottom of sandy soil while it is laid, and has excellent bending fatigue resistance. In addition, there is an advantage that even if it is deformed by a wave or the like, it is excellent in restoring to the original shape.

  A configuration for laminating and integrating the mesh-like body 15 on the sheet 14 will be described. A joining member 30 having a rope through hole 29 as shown in FIG. 5 is integrally attached to the sheet 14 by heat fusion or the like using the same material as the sheet 14. The joining member 30 is provided at a plurality of positions corresponding to the shape of the mesh-like body 15 in the sheet 14. Then, the resin rope 31 passed through the rope through hole 29 of the joining member 30 is also passed through the eyes of the mesh-like body 15 or hooked on the hook provided on the mesh-like body 15, thereby The body 15 can be bundled and integrated with the sheet 14.

  Even when the end portion 19 of the adjacent mat 11 is overlapped with the protruding portion 18 of the sheet 14 shown in FIG. 2, the adjacent mats 11 and 11 can be joined to each other by binding them with a resin rope.

  Similarly, the weight 17 can be held by enclosing the weight 17 with the tip portion 16 of the mesh-like body 15 and passing the resin rope through the mesh-like body 15.

  The scouring prevention mat in which the sheet 14 and the mesh-like body 15 are laminated can be wound in a roll shape except for a portion that wraps the weight 17, and when not in use, It can be stored in a compact state where it is arranged so that the portion enclosing the weight 17 is aligned. In addition, the weight 17 can be wrapped by the tip portion 16 of the mesh-like body 15 in the vicinity of the installation site in water. In this case, the sheet 14 and the mesh-like body 15 are held until the weight 17 is wrapped. It can be wound in a roll shape over its entire length, and therefore can be stored and transported in a more compact state.

  By using the scouring prevention mat 11 having the above-described structure, it is more flexible than the conventional case using a wire mesh, and therefore has good followability to the bottom of the seabed 1 and the like. It is easy, and since it has been given rigidity by heat treatment, it can hardly be deformed such as bending at the bottom of the water, can maintain a stable planar shape, and can have advantages such as no occurrence of rust. .

  In addition, as described above, the weight 17 has a structure in which the end faces of the plurality of concrete blocks 20 are connected by metal fittings, so that the weight 17 is also excellent in followability to the bottom of the seabed 1 or the like. It can be.

It is a figure which shows the use condition of the scouring prevention mat of embodiment of this invention. It is a figure which shows the same scour prevention mat. It is an enlarged detailed view of a mesh-like body. It is a figure which shows the structure of the fiber which comprises a mesh-like body. It is a figure which shows the joining member for binding a mesh-like body to a sheet | seat.

Explanation of symbols

11 Scouring prevention mat 14 Sheet 15 Mesh-like body 17 Weight 27 Core part 28 Sheath part

Claims (6)

A resin-made mesh-like body used for a scour prevention mat, which has a core-sheath cross-sectional structure in which a heat-fusible resin is arranged in a sheath part, and the heat-fusible resin in the sheath part is , Woven and knitted with single or plural fibers having a melting point 10 ° C. or more lower than that of the core resin, and heat-sealing resins are heat-sealed by heat treatment A mesh-like body for a scouring prevention mat characterized by being . The fiber is characterized in that the core is formed of a high-viscosity polyester having an intrinsic viscosity of 0.6 to 1.0, and the sheath is formed of a low-melting polyester having a melting point of 100 to 200 ° C. A mesh-like body for the scouring prevention mat according to Item 1 . 3. A mesh-like body for a scour prevention mat according to claim 1 , wherein the mesh body is composed of warp and weft and is knitted by a weft insertion Raschel knitting machine. A scouring prevention mat, wherein a resin sheet and a mesh-like body for a scouring prevention mat according to any one of claims 1 to 3 are laminated. The scour preventing mat according to claim 4, wherein the mesh-like body is bound to a sheet. At the tip of the mat, scour mat according to claim 4 or 5, wherein the weight is enveloped by the mesh-like body.

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